Stack-Heap Collision problem

ok, trying to script a simple touch activated light and it works, but only once.
imeddiatey following the first click of the switch,it throwsa Stack-Heap Collision Error
script below, any help appreciated

vector color    = <1.0, 1.0, 1.0>;
float intensity = 1.0;
float radius    = 10.0;
float falloff   = 0.0; 
integer channel = 1232;

// do not edit below this line 
toggleLight()
{
    if (llGetPrimitiveParams([PRIM_FULLBRIGHT, 0]))
    { 
        llSetPrimitiveParams([PRIM_FULLBRIGHT, ALL_SIDES, TRUE]);
        llSetPrimitiveParams([PRIM_POINT_LIGHT, 1, color, intensity, radius, falloff]);
        
    }
    else
    {
        llSetPrimitiveParams([PRIM_FULLBRIGHT, ALL_SIDES, FALSE]);
        llSetPrimitiveParams([PRIM_POINT_LIGHT, 0, color, intensity, radius, falloff]);
        
    }
    
}    
default
{
    state_entry()
    {
        llListen(channel, "", NULL_KEY, "" );
    }
    listen(integer a, string n, key id, string m) 
    {
        if ((m == "Touched"))
        {
            toggleLight();
        }
    }
}

hint : llGetPrimitiveParams returns a list...

hehe, yeah, hadn't noticed that in the wiki at first....
finally figured it out and used PRIM_POINT_LIGHT (since it actually returns a true/false) and then check the value of the first index
thanks though